We are HP Service providers, we provide Services and support for Various external clients for Installtion/Integration , HP Hardware (like breakfix, part replacement ) and other OS/application related issues.

We are planning to implement ITIL based Service Managment , initially with Servicedesk ,Incident managment & Problem Managment

Can anyone advice an Service Desk tool which is customizable as per the Data required to be captured (like Serial nos. model nos. etc) with Inventory management (for each client, where Asset details and warranty details are captured) , Customer Contact Database and Setup / Installtion details maintained against each Installation / setup made customer wise.

We are currently evaluating HP Servicedesk, Manageengine Servicedesk plus, VersaDev. We have also heard about BMC remedy for IT service providers.

Remedy is a bit of an exception. It is not so much a service mgt tool, but more of a development platform. It has a lot of possibilities to customize. If it is your choice to have a customized tool, I am not familiair with a better choice. However, there is a great danger of overcustomizing it, with possible supplier-dependancy and a lot of re-customizing when migrating to a newer version.